[chore/performance] Update media prune logic, add extra CLI command (#1474)

* start updating media prune stuff a wee bit

* continue prune / uncache work

* more tidying + consistency stuff

* add prune CLI command

* docs

* arg

internal/processing/media/getfile.go

@@ -33,14 +33,42 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/uris"
 )
 
+// ParseMediaType converts s to a recognized MediaType, or returns an error if unrecognized
+func parseMediaType(s string) (media.Type, error) {
+	switch s {
+	case string(media.TypeAttachment):
+		return media.TypeAttachment, nil
+	case string(media.TypeHeader):
+		return media.TypeHeader, nil
+	case string(media.TypeAvatar):
+		return media.TypeAvatar, nil
+	case string(media.TypeEmoji):
+		return media.TypeEmoji, nil
+	}
+	return "", fmt.Errorf("%s not a recognized media.Type", s)
+}
+
+// ParseMediaSize converts s to a recognized MediaSize, or returns an error if unrecognized
+func parseMediaSize(s string) (media.Size, error) {
+	switch s {
+	case string(media.SizeSmall):
+		return media.SizeSmall, nil
+	case string(media.SizeOriginal):
+		return media.SizeOriginal, nil
+	case string(media.SizeStatic):
+		return media.SizeStatic, nil
+	}
+	return "", fmt.Errorf("%s not a recognized media.Size", s)
+}
+
 func (p *processor) GetFile(ctx context.Context, requestingAccount *gtsmodel.Account, form *apimodel.GetContentRequestForm) (*apimodel.Content, gtserror.WithCode) {
 	// parse the form fields
-	mediaSize, err := media.ParseMediaSize(form.MediaSize)
+	mediaSize, err := parseMediaSize(form.MediaSize)
 	if err != nil {
 		return nil, gtserror.NewErrorNotFound(fmt.Errorf("media size %s not valid", form.MediaSize))
 	}
 
-	mediaType, err := media.ParseMediaType(form.MediaType)
+	mediaType, err := parseMediaType(form.MediaType)
 	if err != nil {
 		return nil, gtserror.NewErrorNotFound(fmt.Errorf("media type %s not valid", form.MediaType))
 	}